On earth in the fifteenth century - to the present day.
China: Too big, too vast to govern efficiently, or effectively. They considereded the rest of the world to be barbarians. Expended all their energy in trying to keep what they had together, became very introverted.
Europe: Fall of the Eatern Roman Empire, the Renaissence and the knowledge that flooded west with the collapse, caused those in the west to question and challenge as they had never done before. We got rid of a church that for centuries had told people what to do and what to think, what was allowed and what wasn't. Major advances in science, technology, medicine and the arts.
Middle East: They adopted a religion and a theocracy that told people what to do and what to think, what was allowed and what wasn't.